Overlapped precast panels and fastening means connecting the same



Jan. 25, 1966 c. D. FOSTER 3,

OVERLAPPED PRECAST PANELS AND FASTENING MEANS CONNECTING THE SAME Filed May a, 19s:

Fl G. 4

FIG.5 a A INVENTOR. CLAYTON. D. FOSTER @43 flawwm ATTYS.

United States Patent 3,230,683 OVERLAPPED PRECAST PANELS AND FASTEN- ING MEANS CONNECTING THE SAME Clayton D. Foster, 1321 SW. Montgomery St, Portland 1, Greg. Filed May 6, 1963, Ser. No. 278,126 2 Claims. (Cl. 52-544) This invention relates to a novel form of joint, and more particularly to a novel joint for connecting structural members in a building or other structure. By using the joint a number of unique advantages are realized. The invention is directed both to the construction of the joint, and to a novel method of erecting a structure Where the joint is employed.

A known method of constructing a building comprises precasting concrete panels or slabs with the slabs in a horizontal position, and after hardening of the slabs shifting them to a vertical position where the slabs then form a wall in the building. A building so made is sometimes referred to as having a tilt-up construction. The precast slabs or panels may also be used in making floors and ceilings, but again, they are lifted into place after precasting them at some other location. The structural joint of this invention is particularly useful as a joint connecting such precast slabs together, and in the description that follows the invention is described in connection with the erection of a building using such precast slabs and a tilt-up method of construction. While the invention is described in such an organization, it is appreciated that certain features of the invention may have utility in making other than wall joints in a building (for instance, a joint according to an embodiment of the invention might be used to connect two beams together).

.age which takes place in precast members over the passage of time, without such shrinkage producing fracturing or other damage.

Yet another object is to provide a joint for two structural members which is attractive to look at.

A still further object is to provide a joint for structural members, where metal fasteners produce a fast connection, and such fasteners are embedded in insulating material in the completed building, thus to be shielded from high heat, whereby the building is more resistant to fire damage.

Explaining the invention in general terms, a method of erecting a concrete building comprises tilting up precast concrete using a derrick or other equipment, to place the slabs in a vertical position. The margins of these panels or slabs are then joined to form a complete building wall. According to this invention, the slabs are precast with passages extending through theirthickness adjacent the margins thereof. During the precasting of the slabs,

anchoring plates are embedded therein between opposite faces of the slabs, in positions where the passages men tioned expose central portions of the plates. In preparing a joint between two panels, for example, these panels are placed in positions where their margins overlap, and passages formed in one panel are aligned and communicate with passages formed in the other. Fasteners may then be placed in the passages with these fasteners con- I I necting the anchor plates embedded in the two slabs. When these fasteners are tightened, the slabs are drawn together to produce a tight joint. The exposed ends of the passages may then be filled with grout, to cover the ends of the fasteners. A wall results with a smooth outer surface, devoid of protruding or exposed fastener ends.

Among the advantages that flow from the invention, as will become more apparent below, is the fact that a minimum amount of equipment such as derricks and the like is needed in forming the wall. The need for separate pillars or pilasters to brace a wall and make it rigid is eliminated. Fitting of the fasteners in proper positions extending between pairs of anchor plates is a relatively easy matter. Further, the joint accommodates shrinkage in the slabs with such absorbed by the fasteners and without cracking in the slabs.

Thus, a more specific object of the invention is to provide a joint for structural members, which comprises passages formed in precast composition panels or other structural members and anchoring plates exposed by the passages, said passages in the joint being aligned and communicating with each other, the jointfurther including fasteners lodged within the passages and connecting together the anchoring plates.

A still further object is to provide a joint for structural components in a building, where fasteners are provided connecting together anchoring plates embedded in the components, said fasteners upon shrinkage of the components being subjected in one embodiment of the invention to shear, and in another embodiment of the invention to tension, and accommodating such shrinkage without damage occurring to the building components themselves.

Another object is to provide, in a building joint of the type described, a construction where fasteners are included connecting embedded anchoring plates, and such fasteners have their ends covered by insulating material,

such as grout, which serves both to form a slightly ex- "members which requires less maintenance than many prior known types of joints.

A still further object is to provide 'a novel method for 'cnstructing a building, which features the use of precast slabs or panels, and fasteners connecting together anchor- 45 -ing plates embedded in these panels or slabs.

prising two precast concrete slabs mounted with margins of the slabs overlapping, and showing a connection connecting the overlapped slab margins together, as contemplated herein;

FIG. 2 is a cross sectional view, taken generally along the line 2-2 in FIG. 1, and further illustrating the con- ,nection between the slab margins;

FIG. 3 is a side view of the building wall illustrated in FIG. 4 is a cross sectional view, generally corresponding to FIG. 2, but illustrating another modification of the invention; and

FIG. 5 is another cross' sectional view, corresponding to FIG. 2, but illustrating a still further modification of the invention.

Referring now to the drawings, and first of all more particularly to FIGS. 1, 2, and 3, 10 and 12 indicate a pair of precast, "composition slabs or panels (ordinarily concrete), erected in a vertical position, and forming a Wall in a building. Margins 10a and 12a of the slabs are overlapped. Completing a joint between the panels or slabs are plural connections 14 disposed in a vertical row along the length of the overlapped margins of the slabs.

Slab is precast with plural passage means disposed in a row extending along the length of the margin thereof that is overlapped with the margin of the other slab. Slab 12 is precast with a similar row of passage means. These passage means, indicated for the two panels individually at 16, typically may be cylindrical in shape, and extend through the thicknesses of the slabs.

Also part of each slab, and embedded in the slab during the precasting thereof, are a plurality of anchoring plates 18. Each of these plates is shown in FIG. 1 as having a rectangular outline, although this is not required and other shapes are possible. The anchoring plates may be made of metal, or other material of suitable strength. One plate is provided at the location of each passage means 16, and such plate is positioned intermediate the faces of the panel containing the passage means, with the plate extending transversely of the passage means, and with central portions of the plate exposed by the passage means.

Each plate 18 has a bore or aperture 20 extending therethrough. This bore preferably is adjacent the center of the passage exposing the plate. Bores 20 accommodate the insertion of the shanks of elongated fasteners therethrough, more specifically bolts such as bolt 21 shown in FIGS. 1 and 2.

With panels or slabs 10, 12 overlapped as shown, the passage means 16 in one panel are aligned and communi cate with the passage means 16 in the other panel. Each connection 14 is formed by passing the shank of a bolt 21 through bores 20 in the pair of anchor plates 18 spanning each set of aligned passages, and tightening a nut 22 on the bolt, whereby the anchor plates, and the panels they are embedded in, are drawn together. As contemplated by this invention, nut 22 of a bolt or fastener, and the head at the other end of the shank of such bolt, each constitute connecting means joined to an end of the shank.

With the nut and bolt assemblies of all the connections 14 tightened, friction between the contacting faces of the overlapped margins of the slabs resists relative movement of the panels or slabs in directions paralleling the planes of the slabs. Such relative movement is also resisted by the various bolts connecting the anchor plates together. It is to be noted that these bolts 'are subjected to shearing stresses when the slabs are moved relative to each other in directions paralleling their planes.

The various nut and bolt assemblies in the joint have ends located inside of outer passage portions 16a of passage means 16. In the completed wall, these outer passage portions of the passage means may be filled with grout 24. As a result, flat outer surfaces in the area of connections 14 are formed. The grout embeds the ends of the fasteners, and thus insulates the fasteners in the joint. Since the fasteners ordinarily are metallic, this is an important factor in obtaining in the wall resistance to extreme heat such as may result from a fire.

With two panels or slabs connected together, by a row of such connections extending along the overlapped margins, an attractive joint results which has considerable strength. No pilasters or similar structural members are needed in making the joint. This is advantageous as it simplifies construction of the wall, and reduces the amount of equipment, such as derricks etc., necessary to erect the wall.

The completed joint accommodates the usual shrinkage that normally occurs in the slabs on ageing of the slabs. Insome types of wall constructions, the joint provided between two slabs is so rigid that it cannot accommodate relative movement of the slabs, and shrinkage is accompanied with cracking the slabs as they are placed in tension. In the construction contemplated, the overlapped margins slide on each other before such cracking occurs, and the fasteners which extend between the two slabs may bend or skew slightly. As a result, cracking in the panels tends to be eliminated, and maintenance costs are minimized.

Another advantage of the joint contemplated is that exact alignment of bores 20 in any two opposed anchor plates is not necessary to enable bolt 21 to be inserted through the bores. The plates are spaced some distance apart, and the bores have a somewhat larger diameter than the diameter of the shank of a bolt. Thus a bolt may be properly fitted in two anchor plates even though it is not. exactly normal to the plates. Thisis quite important in contributing to ease in constructing the wall.

In the prec'asting of the slabs, the usual form may be laid out on the ground, said form defining the edges of a slab, and the slab poured in the form occupying a horizontal plane. At the location of the various passage means, sleeves, such. as sleeves 26'shown in FIG. 2 (of metal, plastic, cardboard, etc.) may be distributed inside the outlines of the form. The sleeves may be used to support the anchor plates in proper position. With the anchor plates and sleeves properly positioned, the concrete may be poured into the form, to produce a slab having the desired passage means, and the anchor plates embedded therein, as described.

Since the panel are flat, after the pouring of one panel,

another panel can be started directly above the one just poured, by suitably mounting the form above the just poured slab and placing additional sleeves and anchor plates within the outline of the form. Thus, it will be noted that by employing flat panels or slabs, precast slabs maybe prepared in a stack, such being advantageous as it reduces the land area required in pr'ecasting the slabs before making the building.

InFIGS. land 2, the sleeves are shown lodged within passage means 16. If desired, they can be removed before tilting up the slabs and fastening them together, to produce a joint without sleeves therein, as shown in FIGS. 4 and 5.

Referring now to FIG. 4, here another modification of the invention is illustrated. In this modification of the invention, slabs or panels '30, 32 are provided with elongated flanges along their margins, shown at 30a and 32a, that occupy planes perpendicular to the planes of the slabs. With two slabs abutted against each other, these flanges parallel each other, and provide reinforcement along the joint in the Wall. Passage means 16 are formed in flanges 30a, 32a. Anchoring plates 18 are embedded in the flanges, between the opposed faces of the flanges, with central portions of the plates exposed by the passage means.

In this modification of the invention, as in the first modification discussed, bolts 21 extend through the passage means and interconnect the anchoring plates. Because of the position of flanges, however, the plates are at right angles to the planes of the slabs, and the bolts therefore parallel the planes of the panels. When shrinkage takes place in the slabs, the bolts are subjected to tension, as compared to the shearing stresses to which the bolts were subjected in the first modification discussed.

In FIG. 4 is will be noted that sleeves corresponding to sleeves 26 are not present in the passages. Thus the outer portions of passage means 16 may be entirely filled with grout in preparing the finished wall. Caulking 28 may also be provided between the slabs where they come together at the joint.

FIG. 5 illustrates yet another modification of the invention. In this instance, slabs 36 and 38 are shown, one of which is prefectly flat, and thus resembles slabs 10 and 12. The other slab has a flange 40 integral therewith, which is offset (laterally from and parallels the plane of the slab of which it is 'a part. Flange 40 overlaps a marginal portion of the adjacent slab. Passages 16 and anchor plates 18 are provided in the zone of overlap.

In this modification of the invention, on shrinkage occurring in the slabs such as results on ageing, the bolts connecting opposed anchor plates are subjected to shear,

as in the first modification of the invention. It will be noted, however, that unlike the structure shown in FIGS. 1, 2 and 3, in the modification of FIG. 5 the slabs occupy one plane. Thus, a fiat wall may be produced.

In the modification of the invention illustrated in FIG. 5, the flat slab or panel may be prepared in the same manner as panels and 12, i.e. by casting one on topof another to form a stack. The other panel does not as easily lend itself to such manufacture as part of a stack, because of the laterally offset flange at one edge thereof. However, it should be noted that only half the total panels used in a wall need be provided with the flanges described.

From the above it should be obvious that the invention has a number of advantages. The joining together of two slabs or panels (or other structural members) is considerably facilitated by providing the embedded anchor plates described, which in a wall joint are grouped as op:- positely disposed pairs, and are easily connected by fasteners extending in the passage means between the plates. A strengthened region is provided along the joint, without necessity of providing an extra element such as a pilaster, and mounting this in place. Shrinkage is accommo-dated without stress or breaking of the slabs. Flat wall surfaces may be produced over the ends of the fasteners, with these then becoming embedded in the finished wall and insulated.

While there has been described various modifications of the invention, it is intended not to be limited only to the specific structures disclosed. Obviously, changes and variations are possible without departing from the invent-ion. It is desired to cover all such modifications that would be apparent to one skilled in the art, and that come within the scope of the appended claims.

I claim:

1. In a building, a pair of panels mounted with portions thereof overlapping, each of said panels containing, between opposite fiaces thereof and in that portion of the panel which overlaps the other panel, an anchoring member having peripheralmargins imbedded in the panel,

a passage to each panel exposing central portions only of that side of the anchoring member in the panel which faces the overlapped portion of the other panel, the passages in the two panels registering and together defining a bore extending between the two panels,

an aperture in the exposed central portion of each anchoring member of smaller diameter than such bore, and

a fastener connecting the panels drawing the overlapped portions together,

said fastener including an elongated shank extending through said bore .and out of contact with the sides thereof, said shank having a diameter which is smaller than the diameter of said apertures and opposite ends that pass through the apertures while being relatively longitudinally shiftable within said apertures, said fastener further including connecting means joined to each end of said shank, larger than said apertures, and bearing against the sides of said anchoring members which are opposite their said first-mentioned sides,

each panel having another passage exposing central portions only of said opposite side of its anchoring member and said other passages in the two panels receiving the connecting means joined to the ends of the fastener in recessed positions between the faces of the panels.

2. The building of claim 1, which further includes a filling material applied to the panels with the fastener connecting the panels, which filling material fills up said other passages and covers the ends of said fastener.

References Cited by the Examiner UNITED STATES PATENTS 1,053,231 2/1913 Schwikert 52-426 1,083,876 1/1914 Craig 52-428 1,462,622 7/1923 Phelan 52-584 1,765,664 6/1930 Plath 52-227 1,964,131 6/1934 Nelson et al 52-396 2,223,016 ll/ 1940 Parkhurst 52-22 2,414,738 1/ 1947 Henderson 52-283 2,698,560 1/1955 Heltzel 94-18 3,064,321 11/ 1962 Rose 20-924 FOREIGN PATENTS 490,809 5/ 1919 France.

640,518 4/ 1928 France.

576,917 4/1945 Great Britain.

330,735 8/ 1958 Switzerland.

FRANK L. ABBOTT, Primary Examiner.

HENRY C. SUTHERLAND, JACOB L. NACKENOFF,

Examiners. 

1. IN A BUIDLING, A PAIR OF PANELS MOUNTED WITH PORTIONS THEREOF OVERLAPPING, EACH OF SAID PANELS CONTAINING, BETWEEN OPPOSITE FACES THEREOF AND IN THAT PORTION OF THE PANELS WHICH OVERLAPS THE OTHER PANELS, AND ANCHORING MEMBER HAVING PERIPHERAL MARGINS IMBEDDED IN THE PANEL, A PASSAGE TO EACH PANEL EXPOSING CENTRAL PORTIONS ONLY OF THAT SIDE OF THE ANCHORING MEMBER IN THE PANEL WHICH FACES THE OVERLAPPED PORTION OF THE OTHER PANEL, THE PASSAGES IN THE TWO PANELS REGISTERING AND TOGETHER DEFINING A BORE EXTENDING BETWEEN THE TWO PANELS, AND APERTURE IN THE EXPOSED CENTRAL PORTION OF EACH ANCHORING MEMBER OF SMALLER DIAMETER THAN SUCH BORE, AND A FASTENER CONNECTING THE PANELS THE OVERLAPPED PORTIONS TOGETHER, SAID FASTENER INCLUDING AN ELONGATED SHANK EXTENDING THROUGH SAID BORE AND OUT OF CONTACT WITH THE SIDES THEREOF, SAID SHANK HAVING A DIAMETER WHICH IS SMALLER THAN THE DIAMETER OF SAID APERTURES AND OPPOSITE ENDS THAT PASS THROUGH THE APERTURES WHILE BEING RELATIVELY LONGITUDINALLY SHIFTABLE WITHIN SAID APERTURES, SAID FASTENER FURTHER INCLUDING CONNECTING MEANS 